Abstract

The evolutionary theory of artefact proper function holds that an artefact’s proper function is that effect which explains the reproduction of past instances of the artefact type. This theory has many sources but received its clearest presentation in Beth Preston’s essay “Why Is a Wing Like a Spoon?”. More recently, Preston has raised an objection to the theory, based on the phenomenon of ‘phantom functions’: these are functions that an artefact type is unable to perform, but which nonetheless apparently constitute its proper function. Deflecting qi energy, for example, is the proper function of feng shui mirrors, even though no feng shui mirror is able to do this. Preston concludes that the existence of phantom functions refutes the evolutionary theory of artefact proper function. In this paper, the evolutionary theory is defended, by arguing that it can adequately account for phantom function cases.